The present invention refers to an attenuator for wave-guides and, more in particular, a so-called “cut-off” attenuator, i.e. a non-dissipative attenuator with working frequencies below the cut-off frequency.
Rectangular wave-guides, that is to say those created in the form of hollow components with a rigid rectangular cross-section along which the microwaves propagate, are currently used in various applications. To create cut-off attenuators for this type of wave-guide, cables placed between two portions of rectangular wave-guide are currently used. This is complicated from a constructional point of view. In particular, a double guide-cable transition is required. For a description of this technique, refer to F. E. Terman “Electronic and Radio Engineering”, (McGraw Hill, New York, 1995, page 154).
In other forms of realization, the attenuator is composed of a plate that is inserted into the rectangular wave-guide. These attenuators also exhibit certain drawbacks known to the experts in this field.